diff -r f516892da470 -r b64e876832cc hw07.tex --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hw07.tex Sun Nov 11 17:28:11 2012 +0000 @@ -0,0 +1,68 @@ +\documentclass{article} +\usepackage{charter} +\usepackage{hyperref} +\usepackage{amssymb} +\usepackage{amsmath} +\usepackage{tikz} +\usetikzlibrary{automata} + +\newcommand{\dn}{\stackrel{\mbox{\scriptsize def}}{=}}% for definitions + +\begin{document} + +\section*{Homework 7} + +\begin{enumerate} +\item Suppose the following finite deterministic automaton over the alphabet $\{0, 1\}$. + +\begin{center} +\begin{tikzpicture}[scale=2, line width=0.5mm] + \node[state, initial, accepting] (q0) at ( 0,1) {$q_0$}; + \node[state, accepting] (q1) at ( 1,1) {$q_1$}; + \node[state] (q2) at ( 2,1) {$q_2$}; + \path[->] (q0) edge[bend left] node[above] {$0$} (q1) + (q1) edge[bend left] node[above] {$1$} (q0) + (q2) edge[bend left=50] node[below] {$1$} (q0) + (q1) edge node[above] {$0$} (q2) + (q2) edge [loop right] node {$0$} () + (q0) edge [loop below] node {$1$} () + ; +\end{tikzpicture} +\end{center} + +Give a regular expression that can recognise the same language as +this automaton. (Hint: If you use Brzozwski's method, you can assume +Arden's lemma which states that an equation of the form $q = q\cdot r + s$ +has the unique solution $q = s \cdot r^*$.) + +\item Consider the following grammar + +\begin{center} +\begin{tabular}{l} +$S \rightarrow N\cdot P$\\ +$P \rightarrow V\cdot N$\\ +$N \rightarrow N\cdot N$\\ +$N \rightarrow A \cdot N$\\ +$N \rightarrow \texttt{student} \;|\; \texttt{trainer} \;|\; \texttt{team} \;|\; \texttt{trains}$\\ +$V \rightarrow \texttt{trains} \;|\; \texttt{team}$\\ +$A \rightarrow \texttt{The} \;|\; \texttt{the}$\\ +\end{tabular} +\end{center} + +where $S$ is the start symbol and $S$, $P$, $N$, $V$ and $A$ are non-terminals. +Using the CYK-algorithm, check whether or not the following string can be parsed +by the grammar: + +\begin{center} +\texttt{The trainer trains the student team} +\end{center} + + +\end{enumerate} + +\end{document} + +%%% Local Variables: +%%% mode: latex +%%% TeX-master: t +%%% End: